title: [Design, clinical suitability and future aspects of a 0.5 T MRI special system for interventional use].
abstract: OBJECTIVE
  To develop a superconducting magnetic resonance (MR) imager that provides direct access to the patient and permits interactive MR-guided interventional procedures.
  
  
  METHODS
  A 0.5-T superconducting magnet that allows a region of vertical access to the patient was designed and constructed. This magnet was integrated with newly designed shielded gradient coils, flexible surface coils, nonmagnetic displays, position-monitoring probes and device-tracking instrumentation.
  
  
  RESULTS
  The magnet homogeneity was 12.3 ppm or better, and the gradient field was linear to within 1% over an imaging region of 30 cm in diameter. The signal-to-noise ratio was 10% higher than in a comparable 0.5-T superconducting imager. Images were obtained in several anatomic regions with use of routine pulse sequences. Interactive image plane selection and near real-time imaging, with use of fast gradient-recalled echo sequences were demonstrated at a rate of one image every 1.5 s. More than 240 procedures (including open brain surgery) have been successfully performed within this environment.
  
  
  CONCLUSIONS
  MR-guided interventional and surgical procedures can be performed with full patient access using an open-configuration, superconducting MR magnet with near real-time imaging and interactive image plane control.
authors.affiliation: Universitätsklinik für Radiodiagnostik, Wien.
authors.forename: J
authors.initials: J
authors.lastname: Kettenbach
authors.forename: S G
authors.initials: SG
authors.lastname: Silverman
authors.forename: R B
authors.initials: RB
authors.lastname: Schwartz
authors.forename: L
authors.initials: L
authors.lastname: Hsu
authors.forename: S K
authors.initials: SK
authors.lastname: Koskinen
authors.forename: R
authors.initials: R
authors.lastname: Kikinis
authors.forename: P M
authors.initials: PM
authors.lastname: Black
authors.forename: F A
authors.initials: FA
authors.lastname: Jolesz
mesh_terms: D019723:Endoscopes; D004867:Equipment Design; D005544:Forecasting; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D015642:Radiology, Interventional / Q000295:instrumentation*
vernacular_title: Aufbau, klinische Eignung und Zukunftsaspekte eines 0,5-T-MR-Spezialsystems für den interventionellen Einsatz.